In the production of molds, for example the pressing out of car body parts, a model is first produced (positive form) which possesses the desired surface characteristics of the part to be pressed out; by means of a casting from this model, a negative mold is then made. With these molds the actual pressed out forms are then produced with the help of a machine tool which calipers the surface of the molds.
However, before the negative mold can be cast from the positive form, it is necessary to apply to the positive form a layer of material which in thickness corresponds to the thickness of the sheet metal which will be used later in the pressing process. It is customary to use self-sticking wax sheeting or lead sheeting for this purpose. Both materials have quite considerable disadvantages. For example, when wrapped around convexities on the surface of the model, they exhibit the tendency to stretch at these elevated spots, resulting in their thickness at these locations not corresponding to the thickness of the sheet metal to be used later in the pressing process. Moreover, these materials are also very susceptible to mechanical influences (fingernails, etc.) and thus are difficult to handle. Grinding and buffing of the surface of these materials is not possible. Smoothing of rough spots, edges and seams with a filler material is not feasible since putty or other filler will not adhere to lead and especially not to a wax surface. Such treatment is, however, important because the surface of the sheeting must be scrupulously smoothed before the casting procedure for the negative mold. In addition, the use of was has the disadvantage that complete removal of the sheeting is very difficult and the residues of wax left on the molds must be cleaned off.
It was the endeavor of the invention to develop a distance sheeting which does not exhibit the aforementioned disadvantages.
This intention has been achieved by a distance sheeting which is described in fuller detail in patent claim 1.